The present invention relates to apparatus for separating at least one component of a gas mixture by pressure swing adsorption of the type called “PSA” or “VSA”, comprising, in a generally vertical vessel comprising an upper dome, at least one adsorbent mass separating a first vertical chamber receiving the gas mixture to be separated, from a second vertical chamber collecting a separated gas mixture, a generally horizontal flexible wall being pressed against the upper end of the adsorbent mass by pressing means.
An apparatus of this type is described in document U.S. Pat. No. 5,176,721 (Hay/Vigor), in the name of the Applicant. In this type of apparatus, in which the gases flow horizontally, the packing membrane separates an upper volume at substantially constant pressure from lower volumes which are alternately subject to sometimes significant pressure variations. This generates a fatigue load on the structural parts of the apparatus (in practice: weld-fabricated metal parts such as grilles, sheets, plates, shells, tubes, ends) which require oversizing (thickness, weld classes, accuracy of adjustments) considerably increasing the manufacturing and installation costs.